許溝(gou)大橋(qiao)位于(yu)洛三高速公路k49+453.37~k49+946.51,三門(men)峽義馬市(shi)近郊,該(gai)橋(qiao)橋(qiao)孔(kong)布置自東向西(xi):9×20m+220m+4×20m,全長493.14m。由(you)中鐵(tie)十一局集團第一工程有限公司施工建(jian)設。
該橋橋孔布(bu)置自東向西:9×20m+220m+4×20m,全長493.14m。主(zhu)孔為等截(jie)面(mian)懸鏈線箱(xiang)形無鉸拱(gong)(gong),截(jie)面(mian)為三(san)室箱(xiang),拱(gong)(gong)軸系(xi)(xi)數m=1.543,凈跨(kua)徑L0=220m,凈矢高f0=40m,矢跨(kua)比f0/L0=1/5.5。拱(gong)(gong)上建筑為13-17.5m先張預應力混(hun)凝(ning)土(tu)空心(xin)板(ban)及雙(shuang)柱式(shi)排架立(li)柱,橋面(mian)連續,柱間設橫向聯系(xi)(xi)。東西引橋為20m預應力混(hun)凝(ning)土(tu)空心(xin)板(ban)梁,橋面(mian)連續,下(xia)部為雙(shuang)柱式(shi)墩臺,基(ji)礎為鉆孔灌(guan)注(zhu)嵌巖樁。
該橋橋寬(kuan)為(wei)(wei)(wei)24m,分上、下行,單幅橋寬(kuan)為(wei)(wei)(wei)12m(11+2×0.5m墻式護欄)。設計(ji)荷載為(wei)(wei)(wei):汽-超20,掛-120。主拱(gong)拱(gong)座為(wei)(wei)(wei)重力(li)式基礎(chu),置于樁基或完整砂巖上。上下行之間(jian)設3cm沉降縫(feng),每個拱(gong)座混(hun)凝(ning)(ning)土量(liang)6000m以(yi)上,屬大體積混(hun)凝(ning)(ning)土,采(cai)取基坑滿(man)注,提高(gao)拱(gong)座背后土抗力(li);主拱(gong)拱(gong)箱采(cai)用C50混(hun)凝(ning)(ning)土。上、下行拱(gong)圈之間(jian)為(wei)(wei)(wei)加強聯結(jie),設6處聯結(jie)系。
許(xu)溝(gou)大橋位于洛三高速(su)公路k49+453.37~k49+946.51,三門峽(xia)義馬市近郊,常窯水(shui)庫下(xia)游,跨越許(xu)溝(gou),溝(gou)中(zhong)常年無(wu)水(shui)。溝(gou)槽(cao)內(nei)地(di)勢(shi)較為(wei)平坦(tan),表層(ceng)(ceng)為(wei)亞砂(sha)土,下(xia)層(ceng)(ceng)為(wei)卵(luan)石層(ceng)(ceng);兩岸地(di)質(zhi)(zhi)較好,表層(ceng)(ceng)有0~3m的(de)沖積亞砂(sha)土和卵(luan)石層(ceng)(ceng),下(xia)層(ceng)(ceng)為(wei)泥質(zhi)(zhi)粉(fen)砂(sha)與粉(fen)砂(sha)質(zhi)(zhi)泥頁巖互層(ceng)(ceng)。該地(di)區最大風力為(wei)20m/s,有霜期為(wei)180~240天。